Present loudspeakers are single-voice coil structures generally, while requirement on the rigidity of a vibrating diaphragm is higher when the vibrating diaphragm is working. Distortion caused by broken vibrating is easily occurred since the present material technology cannot satisfy the requirements of high rigidity, light mass and good damping at the same time. Therefore, the performances of the loudspeakers cannot be improved all the time.
The State Intellectual Property Office of China discloses patents files with publication No. of “CN201657287U” and “CN201854415U”, which disclose double-magnetic system double-voice coil loudspeaker structure, which achieves such advantages as higher driving force, higher magnetic steel utilization ratio and facilitating lighting and thinning of products to a certain extent, but it does not help too much to solve the distortion.